Conservation genetics of whitebark pine (Pinus albicaulis Engelm) in British Columbia
Bibliographic record
Abstract
Pinus albicaulis Engelm. is a keystone subalpine species found throughout mountainous regions of western North America. Population genetic investigations in British Columbia using isozymes (17 populations, 12 loci) extracted from bud tissue revealed that the species has high levels of observed and expected heterozygosity compared to other pine species (0.213 and 0.262, respectively). Isozyme analysis (two populations, ten loci) using maternal gametopyte tissue and embryos extracted from seed elucidated that biparental inbreeding, and possibly selfing, is common (mean multilocus outcrossing rate = 0.73, mean single-locus outcrossing rate = 0.69). There is moderate population substructuring (FST = 0.061), typified by the clumped distribution of trees, influencing gene flow, although seed distribution by Clark's nutcracker appears to be the overriding factor influencing genetic patterns. There were few rare alleles found and genetic distances between populations were small (Nei's 1978 distance ranged from 0.006 to 0.134 and Cavalli-Sforza and Edwards' (1967) chord distance from 0.086 to 0.297). Genetic distances were weakly related to physical distances between populations (Mantel test, p = 0.036). Observed heterozygosity was significantly negatively correlated with longitude (R² = 0.295) and latitude (R² = 0.357). Population genetic parameters were consistent with other studies suggesting northerly postglacial recolonization from refugia in the Washington and Oregon Cascades and several more northern refugia in the Rockies, including the possiblity of a refugium near Roger's Pass, BC. Nearly all populations were observed to have Cronartium ribicola Fisch. (white pine blister rust) infections, mortality of trees of all ages was often present (due to various causes), and regeneration was often sparse or absent. A conservation strategy was developed based on the results of these investigations, concurrent with the priorities and recommendations of other agencies involved with whitebark pine conservation. Priorities included continuing surveys of natural stands in order to identify and monitor putatively resistant trees, collecting seed from all available seed sources and especially these selected individuals, establishing common garden tests to assess adaptive variation and screen for disease resistance, establishing field trials in natural habitats with a variety of hazard ratings for blister rust, developing appropriate seed and scion transfer guidelines, and maintaining a cooperative exchange in terms of materials and research with other jurisdictions involved in whitebark pine conservation. Future research may involve isolation of any specific resistance mechanisms, genetic transformation or cross-breeding of susceptible individuals, and bulk propagation of resistant individuals or families via rooting cuttings or somatic embryogenesis. In the longer term, breeding strategies involving controlled crosses of putatively restitant parents in order to produce hardy and disease resistant planting stock for a variety of hazard-rated sites should be instituted. Due to the extremely long generation time of this species, it is critical that conservation measures begin immediately.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".